TEAS Working Group T. Saad
Internet-Draft V. Beeram
Intended status: Standards Track Juniper Networks
Expires: April 28, 2022 B. Wen
Comcast
D. Ceccarelli
Ericsson
S. Peng
R. Chen
ZTE Corporation
LM. Contreras
Telefonica
X. Liu
Volta Networks
October 25, 2021
YANG Data Model for Slice Policy
draft-bestbar-teas-yang-slice-policy-02
Abstract
A slice policy is a policy construct that enables instantiation of
mechanisms in support of IETF network slice specific control and data
plane behaviors on select topological elements. This document
defines a YANG data model for the management of slice policies on
slice policy capable nodes and controllers in IP/MPLS networks.
Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
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time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on April 28, 2022.
Copyright Notice
Copyright (c) 2021 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3
1.2. Tree Structure . . . . . . . . . . . . . . . . . . . . . 4
2. Slice Policy Data Model . . . . . . . . . . . . . . . . . . . 4
2.1. Model Usage . . . . . . . . . . . . . . . . . . . . . . . 4
2.2. Model Structure . . . . . . . . . . . . . . . . . . . . . 4
2.3. Per-Hop-Behaviors . . . . . . . . . . . . . . . . . . . . 5
2.4. Slice Policies . . . . . . . . . . . . . . . . . . . . . 5
2.4.1. Resource Reservation . . . . . . . . . . . . . . . . 5
2.4.2. Slice Selectors . . . . . . . . . . . . . . . . . . . 6
2.4.3. Per-Hop-Behavior . . . . . . . . . . . . . . . . . . 7
2.4.4. Member Topologies . . . . . . . . . . . . . . . . . . 8
2.5. YANG Module . . . . . . . . . . . . . . . . . . . . . . . 8
3. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 25
4. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 25
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 25
6. Security Considerations . . . . . . . . . . . . . . . . . . . 26
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 27
7.1. Normative References . . . . . . . . . . . . . . . . . . 27
7.2. Informative References . . . . . . . . . . . . . . . . . 28
Appendix A. Complete Model Tree Structure . . . . . . . . . . . 28
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 31
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1. Introduction
An IETF network slice [I-D.ietf-teas-ietf-network-slices] is a well-
defined structure of connectivity requirements and associated network
behaviors. An IETF Network Slice Controller (NSC) is responsible for
the aggregation of multiple IETF network slice traffic streams into a
slice aggregate [I-D.bestbar-teas-ns-packet]. The controller uses a
policy construct called the slice policy to instantiate control and
data plane behaviors on select topological elements associated with
the Network Resource Partition (NRP) that supports a slice aggregate.
An NRP is the collection of resources that are used to support a
slice aggregate. The enforcement of the slice policy results in the
creation of an NRP.
A slice policy specifies the topology associated with the NRP and
dictates how an NRP associated with a slice aggregate can be realized
in IP/MPLS networks using one of three modes. The slice policy
dictates if the partitioning of the shared network resources can be
achieved in (a) just the data plane or in (b) just the control plane
or in (c) both the control and data planes.
The slice policy modes (a) and (c) require the forwarding engine on
each slice policy capable node to identify the traffic belonging to a
specific slice aggregate and to apply the corresponding Per-Hop
Behavior (PHB) that determines the forwarding treatment of the
packets belonging to the slice aggregate. The identification of the
slice aggregate that the packet belongs to and the corresponding
forwarding treatment that needs to be applied to the packet is
dictated by the slice policy.
The slice policy modes (b) and (c) require the distributed/
centralized resource reservation manager in the control plane to
manage NRP resource reservation. The provisions for enabling slice
aggregate aware traffic engineering are dictated by the slice policy.
This document defines a YANG data model for the management of slice
policies on slice policy capable nodes and controllers in IP/MPLS
networks.
1.1. Terminology
The terminology for describing YANG data models is found in
[RFC7950].
The reader is expected to be familiar with the terminology specified
in [I-D.ietf-teas-ietf-network-slices] and
[I-D.bestbar-teas-ns-packet]. The term "Network Slice" used in this
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document must be interpreted as "IETF Network Slice"
[I-D.ietf-teas-ietf-network-slices].
1.2. Tree Structure
A simplified graphical representation of the data model is presented
in Appendix A of this document. The tree format defined in [RFC8340]
is used for the YANG data model tree representation.
2. Slice Policy Data Model
2.1. Model Usage
The onus is on the IETF network slice controller to consume the
network slice service intent and realize it with an appropriate slice
policy. Multiple IETF network slices can be mapped to the same slice
aggregate resulting in the application of the same slice policy. The
network wide consistent slice policy definition (provided by the data
model defined in this document) is distributed to the slice policy
capable nodes and controllers. The specification of the network
slice intent on the northbound interface of the controller and the
mechanism used to associate the network slice to a slice policy are
outside the scope of this document.
2.2. Model Structure
The high-level model structure defined by this document is as shown
below:
module: ietf-slice-policy
+--rw network-slicing!
+--rw phbs
| +--rw phb* [id]
| ............
+--rw slice-policies
+--rw slice-policy* [name]
+ ............
+--rw resource-reservation
| ............
+--rw slice-selectors
| +--rw slice-selector* [index]
| ............
+--rw phb? slice-policy-phb-ref
+--rw member-topologies
+--rw member-topology* [topology-filter]
............
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In addition to the set of slice policies, the top-level container
also includes a placeholder for the set of PHBs that are referenced
by the slice policies.
2.3. Per-Hop-Behaviors
The 'phbs' container carries a list of PHB entries. Each of these
entries can be referenced by one or more slice policies. A PHB entry
can either carry a reference to a generic PHB profile available on
the node or carry a custom PHB profile. The custom PHB profile
includes attributes to construct an NRP specific QoS profile and any
classes within it.
+--rw phbs
| +--rw phb* [id]
| +--rw id uint16
| +--rw (profile-type)?
| +--:(profile)
| | +--rw profile? string
| +--:(custom-profile)
| ............
2.4. Slice Policies
The 'slice-policies' container carries a list of slice policies.
Each slice-policy entry is identified by a name and holds the set of
attributes needed to instantiate the NRP associated with a slice
aggregate. The key elements of each slice-policy entry are discussed
in the following sub-sections.
2.4.1. Resource Reservation
The 'resource-reservation' container carries data nodes that are used
to support slice aggregate aware bandwidth engineering. The data
nodes in this container facilitate preference-based preemption of
slice aggregate aware TE paths, sharing of resources amongst a group
of NRPs and backup path bandwidth protection.
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+--rw resource-reservation
| +--rw preference? uint16
| +--rw (max-bw-type)?
| | +--:(bw-value)
| | | +--rw maximum-bandwidth? uint64
| | +--:(bw-percentage)
| | +--rw maximum-bandwidth-percent?
| | rt-types:percentage
| +--rw shared-resource-groups* uint32
| +--rw protection
| +--rw backup-nrp-id? uint32
| +--rw (backup-bw-type)?
| +--:(backup-bw-value)
| | +--rw backup-bandwidth? uint64
| +--:(backup-bw-percentage)
| +--rw backup-bandwidth-percent?
| rt-types:percentage
2.4.2. Slice Selectors
The 'slice-selectors' container carries a set of data plane field
selectors which are used to identify the packets belonging to the
given slice aggregate. Each slice-selector entry in the list has an
index associated with it. The slice selector with the lowest index
is the default slice selector used by all the topological elements
that are members of the given slice policy. The other entries are
used only when there is a need to override the default slice selector
on some select topological elements.
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+--rw slice-selectors
| +--rw slice-selector* [index]
| +--rw index uint16
| +--rw mpls
| | +--rw (ss-mpls-type)?
| | +--:(label)
| | | +--rw (specification-type)?
| | | +--:(derived)
| | | | +--rw forwarding-label? empty
| | | +--:(explicit)
| | | +--rw label?
| | | | rt-types:mpls-label
| | | +--rw label-position?
| | | | identityref
| | | +--rw label-position-offset? uint8
| | +--:(label-ranges)
| | +--rw label-range* [index]
| | +--rw index string
| | +--rw start-label?
| | | rt-types:mpls-label
| | +--rw end-label?
| | | rt-types:mpls-label
| | +--rw label-position?
| | | identityref
| | +--rw label-position-offset? uint8
| +--rw ipv4
| | +--rw destination-prefix* inet:ipv4-prefix
| +--rw ipv6
| | +--rw (ss-ipv6-type)?
| | +--:(ipv6-destination)
| | | +--rw destination-prefix*
| | | inet:ipv6-prefix
| | +--:(ipv6-flow-label)
| | +--rw slid-flow-labels
| | +--rw slid-flow-label* [slid]
| | +--rw slid inet:ipv6-flow-label
| | +--rw bitmask? uint32
| +--rw acl-ref* slice-policy-acl-ref
2.4.3. Per-Hop-Behavior
The 'phb' leaf carries a reference to the appropriate PHB that needs
to be applied for the given slice aggregate. Unless specified
otherwise, this is the default phb to be used by all the topological
elements that are members of the given slice policy.
+--rw phb? slice-policy-phb-ref
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2.4.4. Member Topologies
The 'member-topologies' container consists of a set of member
topologies. Each member topology references a topology filter
[I-D.bestbar-teas-yang-topology-filter]. The topological elements
that satisfy the membership criteria can optionally override the
default PHB and/or the default slice selector.
+--rw member-topologies
+--rw member-topology* [topology-filter]
+--rw topology-filter
| slice-policy-topo-filter-ref
+--rw slice-selector-override? slice-policy-ss-ref
+--rw phb-override?
slice-policy-phb-ref
2.5. YANG Module
<CODE BEGINS> file "ietf-slice-policy@2021-10-25.yang"
module ietf-slice-policy {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-slice-policy";
prefix sl-pol;
import ietf-inet-types {
prefix inet;
reference
"RFC 6991: Common YANG Data Types";
}
import ietf-routing-types {
prefix rt-types;
reference
"RFC 8294: Common YANG Data Types for the Routing Area";
}
import ietf-network {
prefix nw;
reference
"RFC 8345: A YANG Data Model for Network Topologies";
}
import ietf-access-control-list {
prefix acl;
reference
"RFC 8519: YANG Data Model for Network Access Control Lists
(ACLs)";
}
import ietf-topology-filter {
prefix topo-filt;
reference
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"draft-bestbar-teas-yang-topology-filter: YANG Data Model
for Topology Filter";
}
organization
"IETF Traffic Engineering Architecture and Signaling (TEAS)
Working Group.";
contact
"WG Web: <http://tools.ietf.org/wg/teas/>
WG List: <mailto:teas@ietf.org>
Editor: Vishnu Pavan Beeram
<mailto:vbeeram@juniper.net>
Editor: Tarek Saad
<mailto:tsaad@juniper.net>
Editor: Bin Wen
<mailto:Bin_Wen@cable.comcast.com>
Editor: Daniele Ceccarelli
<mailto:daniele.ceccarelli@ericsson.com>
Editor: Shaofu Peng
<mailto:peng.shaofu@zte.com.cn>
Editor: Ran Chen
<mailto:chen.ran@zte.com.cn>
Editor: Luis M. Contreras
<mailto:luismiguel.contrerasmurillo@telefonica.com>
Editor: Xufeng Liu
<mailto:xufeng.liu.ietf@gmail.com>";
description
"This YANG module defines a data model for managing slice
policies on slice policy capable nodes and controllers.
Copyright (c) 2021 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject to
the license terms contained in, the Simplified BSD License set
forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(https://trustee.ietf.org/license-info).
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This version of this YANG module is part of RFC XXXX; see the
RFC itself for full legal notices.";
revision 2021-10-25 {
description
"Initial revision.";
reference
"RFC XXXX: YANG Data Model for Slice Policies.";
}
/*
* I D E N T I T I E S
*/
/*
* Identity - MPLS Slice Selector Label Position Type
*/
identity ss-mpls-label-position-type {
description
"Base identity for the position of the MPLS label that is used
for slice selection.";
}
identity ss-mpls-label-position-top {
base ss-mpls-label-position-type;
description
"MPLS label that is used for slice selection is at the top of
the label stack.";
}
identity ss-mpls-label-position-bottom {
base ss-mpls-label-position-type;
description
"MPLS label that is used for slice selection is either at the
bottom or at a specific offset from the bottom of the label
stack.";
}
identity ss-mpls-label-position-indicator {
base ss-mpls-label-position-type;
description
"MPLS label that is used for slice selection is preceded by
a special purpose indicator label in the label stack.";
}
/*
* Identity - S-PHB Class Direction
*/
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identity s-phb-class-direction {
description
"Base identity for the direction of traffic to which the Slice
PHB class profile is applied.";
}
identity s-phb-class-direction-in {
base s-phb-class-direction;
description
"Slice PHB class profile is applied to incoming traffic.";
}
identity s-phb-class-direction-out {
base s-phb-class-direction;
description
"Slice PHB class profile is applied to outgoing traffic.";
}
identity s-phb-class-direction-in-out {
base s-phb-class-direction;
description
"Slice PHB class profile is applied to both incoming and
outgoing directions of traffic.";
}
/*
* Identity - S-PHB Class Priority
*/
identity s-phb-class-priority {
description
"Base identity for the priority of the child class scheduler.";
}
identity s-phb-class-priority-low {
base s-phb-class-priority;
description
"Priority of the child class scheduler is low.";
}
identity s-phb-class-priority-strict-high {
base s-phb-class-priority;
description
"Priority of the child class scheduler is strict-high.";
}
/*
* Identity - S-PHB Class Drop Probability
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*/
identity s-phb-class-drop-probability {
description
"Base identity for the drop probability applied to packets
exceeding the CIR of the class queue.";
}
identity s-phb-class-drop-probability-low {
base s-phb-class-drop-probability;
description
"Low drop probability applied to packets exceeding the CIR of
the class queue.";
}
identity s-phb-class-drop-probability-medium {
base s-phb-class-drop-probability;
description
"Medium drop probability applied to packets exceeding the CIR
of the class queue.";
}
identity s-phb-class-drop-probability-high {
base s-phb-class-drop-probability;
description
"High drop probability applied to packets exceeding the CIR of
the class queue.";
}
/*
* T Y P E D E F S
*/
typedef slice-policy-acl-ref {
type leafref {
path "/acl:acls/acl:acl/acl:name";
}
description
"This type is used to reference an ACL.";
}
typedef slice-policy-ss-ref {
type leafref {
path "/network-slicing/slice-policies/slice-policy/"
+ "slice-selectors/slice-selector/index";
}
description
"This type is used to reference a Slice Selector (SS).";
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}
typedef slice-policy-phb-ref {
type leafref {
path "/network-slicing/phbs/phb/"
+ "id";
}
description
"This type is used to reference a Slice Policy Per-Hop
Behavior (S-PHB).";
}
typedef slice-policy-topo-filter-ref {
type leafref {
path "/nw:networks/topo-filt:topology-filters/"
+ "topo-filt:topology-filter/topo-filt:name";
}
description
"This type is used to reference a Slice Policy Topology.";
}
/*
* G R O U P I N G S
*/
/*
* Grouping - Slice Selector MPLS: Label location specific fields
*/
grouping sl-pol-ss-mpls-label-location {
description
"Grouping for MPLS (SS) label location specific fields.";
leaf label-position {
type identityref {
base ss-mpls-label-position-type;
}
description
"MPLS label position - top, bottom with offset, Slice label
indicator.";
}
leaf label-position-offset {
when "derived-from-or-self(../label-position,"
+ "'sl-pol:ss-mpls-label-position-bottom')" {
description
"MPLS label position offset is relevant only when the
label-position is set to 'bottom'.";
}
type uint8;
description
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"MPLS label position offset.";
}
}
/*
* Grouping - Slice Selector (SS)
*/
grouping sl-pol-slice-selector {
description
"Grouping for Slice Selectors.";
container slice-selectors {
description
"Container for Slice Selectors.";
list slice-selector {
key "index";
description
"List of Slice Selectors - this includes the default
selector and others that are used for overriding the
default.";
leaf index {
type uint16;
description
"An index to identify an entry in the slice-selector
list. The entry with the lowest index is the
default slice-selector.";
}
container mpls {
description
"Container for MPLS Slice Selector.";
choice ss-mpls-type {
description
"Choices for MPLS Slice Selector.";
case label {
choice specification-type {
description
"Choices for MPLS label specification.";
case derived {
leaf forwarding-label {
type empty;
description
"MPLS Slice Selector Label is
derived from forwarding label.";
}
}
case explicit {
leaf label {
type rt-types:mpls-label;
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description
"MPLS Slice Selector Label is
explicitly specified.";
}
uses sl-pol-ss-mpls-label-location;
}
}
}
case label-ranges {
list label-range {
key "index";
unique "start-label end-label";
description
"MPLS Slice Selector Label is picked from a
specified set of label ranges.";
leaf index {
type string;
description
"A string that uniquely identifies a label
range.";
}
leaf start-label {
type rt-types:mpls-label;
must '. <= ../end-label' {
error-message
"The start-label must be less than or equal "
+ "to end-label";
}
description
"Label-range start.";
}
leaf end-label {
type rt-types:mpls-label;
must '. >= ../start-label' {
error-message
"The end-label must be greater than or equal "
+ "to start-label";
}
description
"Label-range end.";
}
uses sl-pol-ss-mpls-label-location;
}
}
}
}
container ipv4 {
description
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"Container for IPv4 Slice Selector.";
leaf-list destination-prefix {
type inet:ipv4-prefix;
description
"IPv4 Slice Selector is picked from a specified set of
IPv4 destination prefixes.";
}
}
container ipv6 {
description
"Container for IPv6 Slice Selector.";
choice ss-ipv6-type {
description
"Choices for IPv6 Slice Selector.";
case ipv6-destination {
leaf-list destination-prefix {
type inet:ipv6-prefix;
description
"IPv6 Slice Selector is picked from a specified
set of IPv6 destination prefixes.";
}
}
case ipv6-flow-label {
container slid-flow-labels {
description
"Container for a set of Slice IDs that are
encoded within the flow label.";
list slid-flow-label {
key "slid";
description
"IPv6 Slice Selector is picked from a set of
Slice IDs that are encoded within the flow
label.";
leaf slid {
type inet:ipv6-flow-label;
description
"Slice ID encoded inside the IPv6 flow label.";
}
leaf bitmask {
type uint32;
description
"Bitmask to extract the encoded Slice ID from
the IPv6 flow label.";
}
}
}
}
}
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}
leaf-list acl-ref {
type slice-policy-acl-ref;
description
"Slice Selection is done based on the specified list of
ACLs.";
}
}
}
}
/*
* Grouping - Slice Policy Resource Reservation
*/
grouping sl-pol-resource-reservation {
description
"Grouping for slice policy resource reservation.";
container resource-reservation {
description
"Container for slice policy resource reservation.";
leaf preference {
type uint16;
description
"Control plane preference for the corresponding
Network Resource Partition (NRP). A higher
preference indicates a more favorable resource
reservation than a lower preference.";
}
choice max-bw-type {
description
"Choice of maximum bandwidth specification.";
case bw-value {
leaf maximum-bandwidth {
type uint64;
description
"The maximum bandwidth allocated to an NRP
- specified as absolute value.";
}
}
case bw-percentage {
leaf maximum-bandwidth-percent {
type rt-types:percentage;
description
"The maximum bandwidth allocated to an NRP
- specified as percentage of link
capacity.";
}
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}
}
leaf-list shared-resource-groups {
type uint32;
description
"List of shared resource groups that an NRP
shares its allocated resources with.";
}
container protection {
description
"Container for NRP rotection reservation.";
leaf backup-nrp-id {
type uint32;
description
"The ID that identifies the NRP used for
backup paths that protect primary paths
setup over a specific NRP.";
}
choice backup-bw-type {
description
"Choice of backup bandwidth specification.";
case backup-bw-value {
leaf backup-bandwidth {
type uint64;
description
"The maximum bandwidth on a network resource that
is allocated for backup traffic - specified as
absolute value.";
}
}
case backup-bw-percentage {
leaf backup-bandwidth-percent {
type rt-types:percentage;
description
"The maximum bandwidth on a network resource that
is allocated for backup traffic - specified as
percentage of the link capacity.";
}
}
}
}
}
}
/*
* Grouping - Slice policy PHB (S-PHB)
*/
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grouping sl-pol-phb {
description
"Grouping for S-PHB.";
leaf phb {
type slice-policy-phb-ref;
description
"Reference to a specific PHB from the list of global
PHBs.";
}
}
/*
* Grouping - Slice policy default profile override
*/
grouping sl-pol-override-options {
description
"Grouping of fields that are used to override the default
profile of the slice policy.";
leaf slice-selector-override {
type slice-policy-ss-ref;
description
"Reference to a specific Slice Selector (different from
default).";
}
leaf phb-override {
type slice-policy-phb-ref;
description
"Reference to a specific PHB (different from default).";
}
}
/*
* Grouping - Member Topologies
*/
grouping sl-pol-member-topologies {
description
"Grouping for member topologies.";
container member-topologies {
description
"Container for member topologies.";
list member-topology {
key "topology-filter";
description
"List of member topologies.";
leaf topology-filter {
type slice-policy-topo-filter-ref;
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description
"Reference to a specific topology filter from the list
of global topology filters.";
}
uses sl-pol-override-options;
}
}
}
/*
* Grouping - Per-Hop Behaviors (PHBs)
*/
grouping sl-pol-phbs {
description
"Grouping for PHBs.";
container phbs {
description
"Container for PHBs.";
list phb {
key "id";
description
"List of PHBs.";
leaf id {
type uint16;
description
"A 16-bit ID that uniquely identifies the PHB.";
}
choice profile-type {
description
"Choice of PHB profile type.";
case profile {
description
"Generic PHB profile available on the network
element.";
leaf profile {
type string;
description
"Generic PHB profile identifier.";
}
}
case custom-profile {
description
"Custom PHB profile.";
choice guaranteed-rate-type {
description
"Guaranteed rate is the committed information rate
(CIR) of the slice aggregate that the NRP is
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associated with. The guaranteed rate
also determines the amount of excess (extra)
bandwidth that a group of NRPs can
share. Extra bandwidth is allocated among the
group in proportion to the guaranteed rate of
each associated slice aggregate.";
case rate {
leaf guaranteed-rate {
type uint64;
description
"Guaranteed rate specified as absolute value.";
}
}
case percentage {
leaf guaranteed-rate-percent {
type rt-types:percentage;
description
"Guaranteed rate specified in percentage.";
}
}
}
choice shaping-rate-type {
description
"Shaping rate (peak information rate - PIR)
is the maximum bandwidth of the slice
aggregate that the NRP is associated
with.";
case rate {
leaf shaping-rate {
type uint64;
description
"Shaping rate specified as absolute value.";
}
}
case percentage {
leaf shaping-rate-percent {
type rt-types:percentage;
description
"Shaping rate specified in percentage.";
}
}
}
container classes {
description
"Container for classes.";
list class {
key "class-id";
description
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"List of classes.";
leaf class-id {
type string;
description
"A string to uniquely identify a class.";
}
leaf direction {
type identityref {
base s-phb-class-direction;
}
description
"Class direction.";
}
leaf priority {
type identityref {
base s-phb-class-priority;
}
description
"Priority of the class scheduler. Only one NRP
class queue can be set as a strict-high
priority queue. Strict-high priority
allocates the scheduled bandwidth to
the queue before any other queue receives
bandwidth. Other queues receive the bandwidth
that remains after the strict-high queue has
been serviced.";
}
choice guaranteed-rate-type {
description
"Guaranteed Rate is the Committed information
rate (CIR) of slice aggregate class (that
the NRP is associated with) - specified
as absolute value or percentage.";
case rate {
leaf guaranteed-rate {
type uint64;
description
"Guaranteed rate specified as absolute
value.";
}
}
case percentage {
leaf guaranteed-rate-percent {
type rt-types:percentage;
description
"Guaranteed rate specified in percentage.";
}
}
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}
leaf drop-probability {
type identityref {
base s-phb-class-drop-probability;
}
description
"Drop probability applied to packets exceeding
the CIR of the class queue.";
}
choice maximum-bandwidth-type {
description
"Maximum bandwidth is the Peak information
rate (PIR) of slice aggregate class (that
the NRP is associated with) - specified
as absolute value or percentage.";
case rate {
leaf maximum-bandwidth {
type uint64;
description
"Maximum bandwidth specified as absolute
value.";
}
}
case percentage {
leaf maximum-bandwidth-percent {
type rt-types:percentage;
description
"Maximum bandwidth specified as percentage.";
}
}
}
choice delay-buffer-size-type {
description
"Size of the queue buffer as a percentage of the
dedicated buffer space - specified as value or
percentage.";
case value {
leaf delay-buffer-size {
type uint64;
description
"Delay buffer size.";
}
}
case percentage {
leaf delay-buffer-size-percent {
type rt-types:percentage;
description
"Delay buffer size specified as percentage.";
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}
}
}
}
}
}
}
}
}
}
/*
* Grouping - Slice Policies
*/
grouping sl-policies {
description
"Grouping for slice policies.";
container slice-policies {
description
"Container for slice policies.";
list slice-policy {
key "name";
unique "nrp-id";
description
"List of slice policies.";
leaf name {
type string;
description
"A string that uniquely identifies the slice policy.";
}
leaf nrp-id {
type uint32;
description
"A 32-bit ID that uniquely identifies the NRP
created by the enforcement of this slice
policy.";
}
uses sl-pol-resource-reservation;
uses sl-pol-slice-selector;
uses sl-pol-phb;
uses sl-pol-member-topologies;
}
}
}
/*
* Top-level container - Network Slicing
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*/
container network-slicing {
presence "Enable network slicing.";
description
"Top-level container for network slicing specific constructs
on a slice policy capable network entity.";
uses sl-pol-phbs;
uses sl-policies;
}
}
<CODE ENDS>
3. Acknowledgements
The authors would like to thank Krzysztof Szarkowicz for his input
from discussions.
4. Contributors
The following individuals contributed to this document:
Colby Barth
Juniper Networks
Email: cbarth@juniper.net
Srihari R. Sangli
Juniper Networks
Email: ssangli@juniper.net
Chandra Ramachandran
Juniper Networks
Email: csekar@juniper.net
5. IANA Considerations
This document registers the following URI in the IETF XML registry
[RFC3688]. Following the format in [RFC3688], the following
registration is requested to be made.
URI: urn:ietf:params:xml:ns:yang:ietf-slice-policy
Registrant Contact: The TEAS WG of the IETF.
XML: N/A, the requested URI is an XML namespace.
This document registers a YANG module in the YANG Module Names
registry [RFC6020].
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name: ietf-slice-policy
namespace: urn:ietf:params:xml:ns:yang:ietf-slice-policy
prefix: sl-pol
reference: RFCXXXX
6. Security Considerations
The YANG module specified in this document defines a schema for data
that is designed to be accessed via network management protocols such
as NETCONF [RFC6241] or RESTCONF [RFC8040]. The lowest NETCONF layer
is the secure transport layer, and the mandatory-to-implement secure
transport is Secure Shell (SSH) [RFC6242]. The lowest RESTCONF layer
is HTTPS, and the mandatory-to-implement secure transport is TLS
[RFC8446].
The Network Configuration Access Control Model (NACM) [RFC8341]
provides the means to restrict access for particular NETCONF or
RESTCONF users to a preconfigured subset of all available NETCONF or
RESTCONF protocol operations and content.
The data nodes defined in this YANG module that are
writable/creatable/deletable (i.e., config true, which is the
default) may be considered sensitive or vulnerable in some network
environments. Write operations (e.g., edit-config) to these data
nodes without proper protection can have a negative effect on network
operations. These are the subtrees and data nodes and their
sensitivity/vulnerability:
* "/network-slicing/phbs": This subtree specifies the configurations
for slice policy per-hop behaviors. By manipulating these data
nodes, a malicious attacker may cause unauthorized and improper
behavior to be provided for the slice aggregate traffic on the
network element.
* "/network-slicing/slice-policies": This subtree specifies the
configurations for slice policies on a given network element. By
manipulating these data nodes, a malicious attacker may cause
unauthorized and improper behavior to be provided for the slice
aggregate traffic on the network element.
The readable data nodes in this YANG module may be considered
sensitive or vulnerable in some network environments. It is thus
important to control read access (e.g., via get, get-config, or
notification) to these data nodes. These are the subtrees and data
nodes and their sensitivity/vulnerability:
* "/network-slicing/phbs": Unauthorized access to this subtree can
disclose the slice policy PHBs defined on the network element.
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* "/network-slicing/slice-policies": Unauthorized access to this
subtree can disclose the slice policy definitions on the network
element.
7. References
7.1. Normative References
[I-D.bestbar-teas-ns-packet]
Saad, T., Beeram, V. P., Wen, B., Ceccarelli, D., Halpern,
J., Peng, S., Chen, R., Liu, X., Contreras, L. M., and R.
Rokui, "Realizing Network Slices in IP/MPLS Networks",
draft-bestbar-teas-ns-packet-04 (work in progress),
October 2021.
[I-D.bestbar-teas-yang-topology-filter]
Beeram, V. P., Saad, T., and R. Gandhi, "YANG Data Model
for Topology Filter", draft-bestbar-teas-yang-topology-
filter-01 (work in progress), October 2021.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
DOI 10.17487/RFC3688, January 2004,
<https://www.rfc-editor.org/info/rfc3688>.
[RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for
the Network Configuration Protocol (NETCONF)", RFC 6020,
DOI 10.17487/RFC6020, October 2010,
<https://www.rfc-editor.org/info/rfc6020>.
[RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
and A. Bierman, Ed., "Network Configuration Protocol
(NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
<https://www.rfc-editor.org/info/rfc6241>.
[RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure
Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011,
<https://www.rfc-editor.org/info/rfc6242>.
[RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
RFC 7950, DOI 10.17487/RFC7950, August 2016,
<https://www.rfc-editor.org/info/rfc7950>.
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[RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
<https://www.rfc-editor.org/info/rfc8040>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8341] Bierman, A. and M. Bjorklund, "Network Configuration
Access Control Model", STD 91, RFC 8341,
DOI 10.17487/RFC8341, March 2018,
<https://www.rfc-editor.org/info/rfc8341>.
[RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol
Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
<https://www.rfc-editor.org/info/rfc8446>.
7.2. Informative References
[I-D.ietf-teas-ietf-network-slices]
Farrel, A., Gray, E., Drake, J., Rokui, R., Homma, S.,
Makhijani, K., Contreras, L. M., and J. Tantsura,
"Framework for IETF Network Slices", draft-ietf-teas-ietf-
network-slices-04 (work in progress), August 2021.
[RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams",
BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018,
<https://www.rfc-editor.org/info/rfc8340>.
Appendix A. Complete Model Tree Structure
module: ietf-slice-policy
+--rw network-slicing!
+--rw phbs
| +--rw phb* [id]
| +--rw id uint16
| +--rw (profile-type)?
| +--:(profile)
| | +--rw profile? string
| +--:(custom-profile)
| +--rw (guaranteed-rate-type)?
| | +--:(rate)
| | | +--rw guaranteed-rate? uint64
| | +--:(percentage)
| | +--rw guaranteed-rate-percent?
| | rt-types:percentage
| +--rw (shaping-rate-type)?
| | +--:(rate)
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| | | +--rw shaping-rate? uint64
| | +--:(percentage)
| | +--rw shaping-rate-percent?
| | rt-types:percentage
| +--rw classes
| +--rw class* [class-id]
| +--rw class-id
| | string
| +--rw direction?
| | identityref
| +--rw priority?
| | identityref
| +--rw (guaranteed-rate-type)?
| | +--:(rate)
| | | +--rw guaranteed-rate?
| | | uint64
| | +--:(percentage)
| | +--rw guaranteed-rate-percent?
| | rt-types:percentage
| +--rw drop-probability?
| | identityref
| +--rw (maximum-bandwidth-type)?
| | +--:(rate)
| | | +--rw maximum-bandwidth?
| | | uint64
| | +--:(percentage)
| | +--rw maximum-bandwidth-percent?
| | rt-types:percentage
| +--rw (delay-buffer-size-type)?
| +--:(value)
| | +--rw delay-buffer-size?
| | uint64
| +--:(percentage)
| +--rw delay-buffer-size-percent?
| rt-types:percentage
+--rw slice-policies
+--rw slice-policy* [name]
+--rw name string
+--rw nrp-id? uint32
+--rw resource-reservation
| +--rw preference? uint16
| +--rw (max-bw-type)?
| | +--:(bw-value)
| | | +--rw maximum-bandwidth? uint64
| | +--:(bw-percentage)
| | +--rw maximum-bandwidth-percent?
| | rt-types:percentage
| +--rw shared-resource-groups* uint32
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| +--rw protection
| +--rw backup-nrp-id? uint32
| +--rw (backup-bw-type)?
| +--:(backup-bw-value)
| | +--rw backup-bandwidth? uint64
| +--:(backup-bw-percentage)
| +--rw backup-bandwidth-percent?
| rt-types:percentage
+--rw slice-selectors
| +--rw slice-selector* [index]
| +--rw index uint16
| +--rw mpls
| | +--rw (ss-mpls-type)?
| | +--:(label)
| | | +--rw (specification-type)?
| | | +--:(derived)
| | | | +--rw forwarding-label? empty
| | | +--:(explicit)
| | | +--rw label?
| | | | rt-types:mpls-label
| | | +--rw label-position?
| | | | identityref
| | | +--rw label-position-offset? uint8
| | +--:(label-ranges)
| | +--rw label-range* [index]
| | +--rw index string
| | +--rw start-label?
| | | rt-types:mpls-label
| | +--rw end-label?
| | | rt-types:mpls-label
| | +--rw label-position?
| | | identityref
| | +--rw label-position-offset? uint8
| +--rw ipv4
| | +--rw destination-prefix* inet:ipv4-prefix
| +--rw ipv6
| | +--rw (ss-ipv6-type)?
| | +--:(ipv6-destination)
| | | +--rw destination-prefix*
| | | inet:ipv6-prefix
| | +--:(ipv6-flow-label)
| | +--rw slid-flow-labels
| | +--rw slid-flow-label* [slid]
| | +--rw slid
| | | inet:ipv6-flow-label
| | +--rw bitmask? uint32
| +--rw acl-ref* slice-policy-acl-ref
+--rw phb? slice-policy-phb-ref
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+--rw member-topologies
+--rw member-topology* [topology-filter]
+--rw topology-filter
| slice-policy-topo-filter-ref
+--rw slice-selector-override?
| slice-policy-ss-ref
+--rw phb-override?
slice-policy-phb-ref
Authors' Addresses
Tarek Saad
Juniper Networks
Email: tsaad@juniper.net
Vishnu Pavan Beeram
Juniper Networks
Email: vbeeram@juniper.net
Bin Wen
Comcast
Email: Bin_Wen@cable.comcast.com
Daniele Ceccarelli
Ericsson
Email: daniele.ceccarelli@ericsson.com
Shaofu Peng
ZTE Corporation
Email: peng.shaofu@zte.com.cn
Ran Chen
ZTE Corporation
Email: chen.ran@zte.com.cn
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Luis M. Contreras
Telefonica
Email: luismiguel.contrerasmurillo@telefonica.com
Xufeng Liu
Volta Networks
Email: xufeng.liu.ietf@gmail.com
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